1. Field of the Invention
This invention relates generally to a method and composition for cleaning contact lenses. In one aspect, the present invention relates to a method and composition for cleaning contact lenses with cyclodextrins while in another aspect it relates to a method for simultaneously cleaning and disinfecting contact lenses by contacting the lenses with compositions containing cyclodextrins either under elevated temperatures or in the presence of antimicrobial agents.
2. Description of Art
In the normal course of wearing contact lenses, tear film and debris consisting of proteinaceous, oily, sebaceous, and related organic matter have a tendency to deposit and build up on lens surfaces. As part of the routine and proper care regimen, contact lenses must be cleaned to remove these tear film deposits and debris. If these deposits are not properly removed, both the wettability and optical clarity of the lenses are substantially reduced causing discomfort for the wearer.
Conventionally, the cleaning of contact lenses is accomplished with one or both of two general classes of cleaners. Surfactant cleaners, generally known as "daily cleaners" because of their recommended daily use, are effective for the removal of most carbohydrate and lipid derived matter. However, they are not as effective for the removal of proteinaceous matter such as lysozyme. Proteolytic enzymes derived from plant, animal, and microbial sources are generally used to remove the proteinaceous deposits. These "enzyme" cleaners are typically recommended for weekly use and are conventionally employed by dissolving enzyme-containing tablets in suitable solutions. Both cleaners are currently recommended for proper care of contact lenses, particularly those made from hydrophilic materials.
Cyclodextrins have been known for nearly a century being first isolated from the degradation products of starch. They are cyclic oligosaccharides produced by the enzymatic degradation of starch. The degradation enzymes used are typically produced by various microorganisms such as bacilli. Generally, cyclodextrins have been commercially employed in the pharmaceutical industry as inclusion or entrapment agents for the purpose of solubilizing relatively insoluble compounds preventing the evaporation of volatile compounds stabilizing volatile or heat labile compounds, enhancing the bioavailability of certain drugs and related purposes. Hence, conventional uses of cyclodextrins involve the inclusion of an active compound into the cyclodextrin molecular structure prior to use and employ the cyclodextrin as a means for delivering the active compound.
It has now been found that cyclodextrin compositions can be employed under ambient and elevated temperatures to remove many of the deposits, which adhere to contact lenses during normal wear including, proteinaceous matter, typically the most difficult deposits to remove. These compositions contain cyclodextrins which do not contain active compounds incorporated into the cavity of the cyclodextrin. Moreover, it has been surprisingly found that the continued and regular use of cyclodextrin cleaning compositions result in an effective technique for preventing proteinaceous deposit build-up on contact lenses.